The calls by a growing number of recently retired generals for the resignation of Defense Secretary Donald Rumsfeld have created the most serious public confrontation between the military and an administration since President Harry S. Truman fired Gen. Douglas MacArthur in 1951. In that epic drama, Truman was unquestionably correct -- MacArthur, the commanding general in Korea and a towering World War II hero, publicly challenged Truman's authority and had to be removed. Most Americans rightly revere the principle that was at stake: civilian control over the military. But this situation is quite different.

First, it is clear that the retired generals -- six so far, with more likely to come -- surely are speaking for many of their former colleagues, friends and subordinates who are still inside. In the tight world of senior active and retired generals, there is constant private dialogue. Recent retirees stay in close touch with old friends, who were often their subordinates; they help each other, they know what is going on and a conventional wisdom is formed. Retired Marine Lt. Gen. Greg Newbold, who was director of operations for the Joint Chiefs of Staff during the planning period for the war in Iraq, made this clear in an extraordinary, at times emotional, article in Time magazine this past week when he said he was writing "with the encouragement of some still in positions of military leadership." He went on to "challenge those still in uniform . . . to give voice to those who can't -- or don't have the opportunity to -- speak."

These generals are not newly minted doves or covert Democrats. (In fact, one of the main reasons this public explosion did not happen earlier was probably concern by the generals that they would seem to be taking sides in domestic politics.) They are career men, each with more than 30 years in service, who swore after Vietnam that, as Colin Powell wrote in his memoirs, "when our turn came to call the shots, we would not quietly acquiesce in half-hearted warfare for half-baked reasons." Yet, as Newbold admits, it happened again. In the public comments of the retired generals one can hear a faint sense of guilt that, having been taught as young officers that the Vietnam-era generals failed to stand up to Defense Secretary Robert McNamara and President Lyndon Johnson, they did the same thing.

Second, it is also clear that the target is not just Rumsfeld. Newbold hints at this; others are more explicit in private. But the only two people in the government higher than the secretary of defense are the president and vice president. They cannot be fired, of course, and the unspoken military code normally precludes direct public attacks on the commander in chief when troops are under fire. (There are exceptions to this rule, of course: In addition to MacArthur, there was Gen. George McClellan vs. Lincoln; and on a lesser note, Maj. Gen. John Singlaub, who was fired for attacking President Jimmy Carter over Korea policy. But such challenges are rare enough to be memorable, and none of these solo rebellions metastasized into a group, a movement that can fairly be described as a revolt.)

This has put President Bush and his administration in a hellish position at a time when security in Iraq and Afghanistan seems to be deteriorating. If Bush yields to the generals' revolt, he will appear to have caved in to pressure from what Rumsfeld disingenuously describes as "two or three retired generals out of thousands." But if he keeps Rumsfeld, he risks more resignations -- perhaps soon -- from generals who heed Newbold's stunning call that as officers they took an oath to the Constitution and should now speak out on behalf of the troops in harm's way and to save the institution that he feels is in danger of falling back into the disarray of the post-Vietnam era.

Facing this dilemma, Bush's first reaction was exactly what anyone who knows him would have expected: He issued strong affirmations of "full support" for Rumsfeld, even going out of his way to refer to the secretary of defense as "Don" several times in his statements. (This was in marked contrast to his tepid comments on the future of his other embattled Cabinet officer, Treasury Secretary John Snow. Washington got the point.)

In the end, the case for changing the secretary of defense seems to me to be overwhelming. I do not reach this conclusion simply because of past mistakes, simply because "someone must be held accountable." Many people besides Rumsfeld were deeply involved in the mistakes in Iraq and Afghanistan; many of them remain in power, and some are in uniform.

The major reason the nation needs a new defense secretary is far more urgent. Put simply, the failed strategies in Iraq and Afghanistan cannot be fixed as long as Rumsfeld remains at the epicenter of the chain of command. Rumsfeld's famous "long screwdriver," with which he sometimes micromanages policy, now thwarts the top-to-bottom reexamination of strategy that is absolutely essential in both war zones. Lyndon Johnson understood this in 1968 when he eased another micromanaging secretary of defense, McNamara, out of the Pentagon and replaced him with Clark M. Clifford. Within weeks, Clifford had revisited every aspect of policy and begun the long, painful process of unwinding the commitment. Today, those decisions are still the subject of intense dispute, and there are many differences between the two situations. But one thing was clear then and is clear today: Unless the secretary of defense is replaced, the policy will not and cannot change.

That first White House reaction will not be the end of the story. If more angry generals emerge -- and they will -- if some of them are on active duty, as seems probable; if the situation in Iraq and Afghanistan does not turn around (and there is little reason to think it will, alas), then this storm will continue until finally it consumes not only Donald Rumsfeld. The only question is: Will it come so late that there is no longer any hope of salvaging something in Iraq and Afghanistan?

Richard Holbrooke, a former U.S. ambassador to the United Nations, writes a monthly column for The Post.